Irregular migrants, being defined as asylum seekers, refugees and clandestinos (people in the EU without a valid residency permit), live as a subaltern group at the fringes of European society. They are materially deprived and excluded from regular political culture. In part, this condition stems from the institutions of European integration, such as the Dublin Regulation. This dissertation attempts to understand irregular migrant subalternity by exploring its structural causes. Irregular migration and its management is used as a case study to contribute towards a deeper understanding of the social purpose of European integration. Methodologically, this thesis relies on Critical Grounded Theory. This novel approach is rooted in critical realism and thus rejects the tabula rasa-view of traditional Grounded Theory, maintaining that empirics and theory should continuously inform one another. The Gramscian concept of hegemony is employed to contextualise European integration within neofunctionalism as an ideological practice and neoliberalism as a hegemonic agenda. Vulgar neofunctionalism postulates that integration occurs as the result of spillover of one policy area into another and that European integration is pushed forward by technocratic elites. To illustrate the relationship between neofunctionalism and neoliberalism, to lay bare the consequences of neoliberal and neofunctionalist practices, and to further capture the social purpose of European integration, fieldwork was carried out in five locations (Brussels, Greece, Bulgaria, Italy and Germany) with different groups of interviewees (European Commission staff, national public officials, asylum seekers, clandestinos, fruit farm workers, asylum accommodation staff). It was found that neoliberal neofunctionalism has generated a common outlook on migratory movements which has resulted in the partial harmonisation of asylum legislation and the simultaneous fortification of the EU’s external border. This has had a significant impact on the lives of irregular migrants, who are exposed to reification, commodification, biopolitics, the state of exception, xenophobia and lacking recognition. The emergence of group consciousness is undermined, preventing them from overcoming subalternity. The social purpose of European integration is identified as the (increasingly authoritarian) neoliberal restructuration of the EU which relies on neofunctionalism as its vehicle and justification. This restructuration is self-contradictory as it aims at neoliberalism while producing nationalism, biopolitics and the EU’s deepening internal division. Within the context of the European Union’s democratic deficit and the weakness of social democracy, nationalism may represent an alternative to neoliberalism, speeding up the EU’s disintegration.